Nuclear transition probability, B(E2), for 0g.s.+ – 2first+ transitions and deformation parameter, β2

Adopted values for the reduced electromagnetic transition probability, B(E2)_ex, from the ground to the first-excited 2⁺-state of even-even nuclei are given in Table I. Values of β₂, the quadrupole deformation parameter, and of T, the mean life of the 2⁺ state, are also listed there.

Table II presents the data on which Table I is based, namely the experimental results for B(E2)_ex values with quoted errors. The literature has been covered to January 1965.

The ratio of the value of β₂ to values expected from the single-particle model is presented graphically as a function of neutron number. As an indication of the extent of collective features in nuclear structure, this ratio seems a better measure than the value of β₂ itself.